In the automotive field, bumpers are vehicle structures that are typically positioned at the front and rear of the vehicle. Functions performed by bumpers include preventing damage to other portions of the vehicle during a low-speed collision, absorbing energy during higher speed collisions, and reducing the extent of height mismatch between vehicles of different sizes.
Bumpers often protrude longitudinally forward with respect to other vehicle structures such as body panels, or longitudinally rearward of other vehicle structures. In the event of a collision at the front or rear of a vehicle, the bumper is often the first part of the vehicle that is struck. A number of vehicle bumper structures have been utilized. A simple design includes a laterally extending metal beam that is supported forward of other vehicle structures by two or more support structures. Many modern designs include a plastic bumper cover that conceals an underlying bumper structure that is designed to absorb impact by crushing, such as a cellular structure formed from plastic.